U.S. Pat. No. 4,628,875 describes a cylinder head and a rocker shaft mounting assembly. The assembly comprises four pedestal mounts, each of which is fixed to the head by means of two bolts that engage bores machined in the cylinder head. A separate cap is associated with each pedestal mount. The cap and mount are machined such that when they are bolted together they form a bore that embraces the rocker shaft and fixes the rocker shaft to the cylinder head. This arrangement requires the use of a relatively large number of components, which results in increased production and assembly costs.